Ukraine President Volodymyr Zelenskyy called on the United States and Western nations to send more air defense weapons, including F-16 jet fighters, to his nation as Russian forces have made critical gains in northeast Ukraine in the past week.

He also argued for lifting restrictions against using the arms to strike inside Russia.

"They can fire any weapons from their territory at ours. This is the biggest advantage that Russia has. We can't do anything to their systems, which are located on the territory of Russia, with Western weapons," he said.

In an interview with Agence France-Presse on Friday, Zelenskyy said his country only has "about 25% of what we need" to defend itself against Russia in terms of air defense. 

He estimated that Ukraine would need up to 130 F-16 jets or similar advanced aircraft to reach "parity" with Russia.

But despite the critical gains Russian troops have made in northeast Ukraine in the past week, Zelenskyy, who has rallied the country since the February 2022 invasion, vowed: "No one is going to give up."

He said that Russia troops have advanced up to 6 miles along the northeast border before being halted by Ukrainian forces.

The region has been "controlled" not "stabilized," he said.

"I won't say it's a great success [for Russia[ but we have to be sober and understand that they are going deeper into our territory," he said in the interview from Kyiv.

Although Ukrainian forces are outmanned and outgunned in the region, Zelenskyy said they will continue to resist Russia. 

Addressing President Vladimir Putin's comments that Russia has no plans to capture Kharkiv "as of today," Zelenskyy said Russian forces could find it "very difficult."

They "understand that we have forces that will fight for a long time," he said.

Zelenskyy said Moscow lacks the forces for "a full-scale offensive on the capital like the one they had at the beginning of the offensive."

But he warned the U.S. and its Western allies not to show weakness, and reiterated his call for Patriot missile systems to protect the skies around Kharkiv from Russia.

"They are like a beast. ... If they feel a weakness somewhere in this direction, they will press on," he said.